Adipose-derived adult stromal/stem (ADAS) cells pose exciting opportunities for the field of biomedical engineering. ADAS cells provide an ample source of multipotent cells for tissue regeneration procedures. Current research has shown that these cells can be differentiated into a variety of cell types. Media supplements can help guide the stem cells towards specific lineages of interest: chondrocytic, osteoblastic, and adipocytic. The goal of this study is to determine the extent of biomechanical change for a stem cell during differentiation. We hypothesize that a cell's biomechanical properties will change slowly during the differentiation process but will eventually diverge to become more characteristic of a specific cell type. To test this, we will determine the elastic and viscoelastic properties of single, ADAS cells during differentiation using atomic force microscopy. Mechanical properties that will be obtained include instantaneous, relaxed, and Young's moduli and apparent viscosity. Comparison with primary cell types will help determine whether ADAS cells successfully differentiate in terms of cellular biomechanics. These studies will significantly improve our understanding of the cellular-level changes that occur during the stem cell differentiation process. [unreadable] [unreadable]